Actress Amanda Holden has revealed her marriage was effectively over nearly three years before she split from Les Dennis.

Opening her heart for the first time since the separation last December, the Cutting It star said her fling with actor Neil Morrissey in 2000 was an indication "the marriage was over".

In an interview for BBC1's Parkinson to be screened tonight, Holden said she is now "flabbergasted" at her behaviour in conducting the affair so publicly.

"The affair was a terrible mistake and something I regret," she said. "I regret the amount of pain I caused Les and everyone involved. It was an awful, traumatic time.

"But that was a huge indication that there were problems within my marriage."

Holden and Men Behaving Badly star Morrissey were photographed walking together in May 2000.

It led to Holden and Dennis announcing a trial separation, but they tried to give their marriage another chance until the end was formally announced four months ago.

Holden told host Michael Parkinson the 16-year age gap did not bother her at first. But she said: "I think that between the ages of 22 and 32, which is what I am now, I changed dramatically and what I wanted from life changed as well. We were completely exhausted with trying, with making it work."

Although keen to have children, she did not want them as quickly. "I think that the age thing came in there because Les probably wanted them a lot sooner."

Currently single, she added that the interest in her private life meant "it's going to take a very brave man to love me and stay with me".

After recording the show on Thursday night the actress said talking to Parkinson was "cheaper than therapy".